JP2009057653A - Method for producing dyed yarn, dyed yarn, and carpet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dyed yarn obtained by mixing a polylactic acid fiber obtained by suppressing the reduction of properties of a polylactic acid, and having excellent color fastness to dyeing, with other fibers, to provide a method for producing the dyed yarn, and to provide a polylactic acid-based carpet having excellent soft feeling, voluminousness, wear resistance and color fastness to dyeing. <P>SOLUTION: The method for producing the dyed yarn includes a step for imparting another dye having dyeing behavior different from that of a disperse dye to a mixed yarn obtained by mixing fiber of polylactic acid with other fibers, and thereafter imparting the disperse dye thereto. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blended yarn.

  At present, polylactic acid, which is a kind of aliphatic polyester, has attracted the most attention as a biodegradable polymer utilizing biomass. Currently, polylactic acid that can be used as industrial fibers has low wear resistance. For applications that require wear resistance, such as carpets, blended yarn containing polylactic acid fibers and non-polylactic acid fibers is used. A method of improving wear resistance by forming a surface layer by using the surface layer is employed (for example, see Patent Document 1).

  And since polylactic acid is also easily degradable, as a method for dyeing polylactic acid fibers that are likely to deteriorate even in the dyeing process, by selecting the dyeing temperature, dyeing pH and dyeing time, before and after dyeing polylactic acid fibers A method of suppressing the retention of tensile strength and the decrease in weight average molecular weight is disclosed (for example, see Patent Document 2). However, under the conditions disclosed in this document, it has been difficult to effectively dye non-polylactic acid fibers in the mixed yarn. Moreover, when matched with the dyeing | staining conditions of non-polylactic acid fiber, there existed a problem that degradation will be accelerated | stimulated.

  Moreover, there is also a problem in that the production efficiency is low when the polylactic acid fiber and the non-polylactic acid fiber are separately dyed and then mixed.

On the other hand, as a dyeing method that can shorten the dyeing time and reduce the amount of liquid necessary for the dyeing bath, there is a technique called space dyeing dyeing (for example, see Patent Document 3). However, in this technique, although a device and a method for applying a pattern by applying a dye of a different color to a designated portion of a yarn and making a pattern have been disclosed, a yarn composed of a plurality of types of fibers such as a mixed yarn, There has been no suggestion about a method for selectively dyeing fiber types.
JP-A-2005-245706 (Claims 1, 4 and 5) JP-A-8-311781 (Claims 1, 2, 3, 4, 6) JP-A-9-105071 (Claim 1)

  An object of the present invention is to provide a blended yarn that suppresses deterioration of physical properties of polylactic acid fibers and is excellent in dyeing fastness of both polylactic acid fibers and other fibers.

  That is, the present invention provides a process for applying a disperse dye after adding another dye having a dyeing action different from that of a disperse dye to a mixed fiber formed by mixing fibers made of polylactic acid resin and other fibers. Is a method for producing a dyed yarn.

  The present invention also provides a fiber made of polylactic acid resin and a fiber made of polylactic acid resin, and other fibers dyed with another dye having a different dyeing action from the disperse dye. Are dyed, the polylactic acid resin has a weight average molecular weight of 130,000 or more, the tensile strength of the fiber made of the polylactic acid resin is 1.5 cN / dtex or more, and light fastness as a dyed yarn The dyed yarn is characterized in that both the fastness to friction and fastness to washing are grade 3 or higher.

  The present invention is also a carpet characterized by using the dyed yarn of the present invention.

  According to the present invention, a mixed yarn containing polylactic acid fibers dyes both polylactic acid fibers and other fibers to a desired color while suppressing deterioration of the physical properties of the fibers, and excellent dyeing fastness. Sex can be imparted.

  In addition, the dyed yarn of the present invention is excellent in strength and dyeing fastness, while fibers made of a polylactic acid resin and other fibers dyed with another dye having a different dyeing action from the disperse dye are mixed.

  In the method for producing a dyed yarn of the present invention, the mixed yarn before dyeing includes fibers made of polylactic acid resin. Among the biodegradable polymers using biomass, polylactic acid has an excellent balance of mechanical properties, heat resistance, and cost.

Polylactic acid is a polymer having — (O—CHCH ₃ —CO) _n — as a repeating unit, and is obtained by polymerizing oligomers of lactic acid such as lactic acid and lactide.

  Lactic acid has two optical isomers, D-form and L-form. In either L-form or D-form, the higher the optical purity of polylactic acid, the higher the melting point of polylactic acid, that is, heat resistance is improved. Therefore, it is preferable. The optical purity of polylactic acid is preferably 95% or more. The melting point of polylactic acid is preferably 150 ° C. or higher in order to maintain the heat resistance of the fiber.

  Usually, residual lactide may be present as a low molecular weight residue in polylactic acid, but the residual lactide amount in polylactic acid is preferably 3000 ppm by mass or less, more preferably 1000 ppm by mass or less, and even more preferably 300 ppm. The mass is ppm or less. By suppressing the amount of residual lactide in the polylactic acid, it is possible to prevent abnormal dyeing such as heating-heater dirt in the stretching or false twisting process and dyed spots in the dyeing process.

  In addition, components other than lactic acid may be copolymerized as long as the biodegradability of polylactic acid is not impaired. The components to be copolymerized include polyalkylene ether glycols such as polyethylene glycol, aliphatic polyesters such as polybutylene succinate and polyglycolic acid, aromatic polyesters such as polyethylene isophthalate, and hydroxycarboxylic acids, lactones, dicarboxylic acids, and diols. An ester bond-forming monomer such as

  The weight average molecular weight (Mw) of the polylactic acid is important to maintain at least 130,000 for maintaining the wear resistance, preferably 150,000 or more, more preferably 170,000 or more. On the other hand, the weight average molecular weight of polylactic acid is preferably 350,000 or less, more preferably 300,000 or less, and even more preferably 250,000 or less, in order to maintain stretchability and thus fiber strength by molecular orientation.

  The polylactic acid resin may contain particles, a crystal nucleating agent, a flame retardant, a plasticizer, a terminal blocking agent, an antistatic agent, an antioxidant, an ultraviolet absorber, a lubricant such as ethylenebissteasanamide, and the like.

  Examples of the terminal blocking agent include carbodiimide compounds such as polycarbodiimide, and compounds having a glycidyl group such as diallyl monoglycidyl isocyanurate, monoallyl diglycidyl isocyanurate, and tridiglycidyl isocyanurate.

  As addition amount with respect to polylactic acid of a terminal blocker, 0.1-10 mass% is preferable. By setting the content to 0.1% by mass or more, the durability of the polylactic acid fiber can be improved. Further, if 10% by mass is added, the end groups are sufficiently blocked, and if it exceeds 10% by mass, the effect of improving durability is saturated.

  The cross-sectional shape of the fiber made of polylactic acid resin includes a round cross section, a hollow cross section, a porous hollow cross section, a multileaf cross section such as a trilobal cross section (triangular cross section, Y cross section, T cross section, etc.), flat cross section, W cross section, X cross section. Etc. can be adopted. Among these, a modified cross section is preferable for improving the bulkiness. The irregularity of the irregular cross section is preferably 1.1 to 8.0, more preferably 1.3 to 7.0. Here, the degree of irregularity is represented by the ratio of the diameter of the circumscribed circle to the diameter of the inscribed circle in the cross section. By making the degree of irregularity 1.1 or more, it is possible to obtain an effect of improving the bulkiness due to the irregular cross section. Moreover, fibrillation of a fiber can be prevented by setting it as 8.0 or less.

  The fibers made of the polylactic acid resin in the dyed yarn of the present invention preferably have crimps. By doing so, the texture as a carpet can be obtained in a carpet use.

  The tensile strength of the fiber made of polylactic acid resin in the dyed yarn of the present invention is important to be 1.5 cN / dtex or more, preferably 1.6 cN / dtex or more. By setting it to 1.5 cN / dtex or more, yarn breakage during tufting in carpet processing can be prevented, and durability as a carpet can be improved.

  The tensile elongation of the fiber made of polylactic acid resin in the dyed yarn of the present invention is preferably 40% or more, more preferably 45% or more. By setting it to 40% or more, yarn breakage during tufting in carpet processing can be prevented, and durability as a carpet can be improved.

  The fiber made of polylactic acid resin in the dyed yarn of the present invention preferably has a tensile strength retention and a weight average molecular weight retention before dyeing processing of 90% or more, more preferably 95% or more. By doing so, durability of the polylactic acid fiber at the time of carpet use can be improved.

  It is important that the mixed yarn before dyeing in the method for producing a dyed yarn of the present invention includes fibers other than fibers made of polylactic acid resin. Polylactic acid fibers are less prone to wear than other general-purpose fibers, and are inferior in wear resistance. By blending “other fibers” that have better wear resistance than polylactic acid, The wear resistance, which is a weak point, can be compensated.

  As the “other fiber” thermoplastic resin, thermoplastic polyamide, polyacetal, polypropylene, polyethylene, and the like can be preferably used from the viewpoint of improving the wear resistance.

  Among these, thermoplastic polyamides are particularly preferable from the viewpoints of easily imparting crimps by heating fluid treatment and the like, and feeling of supple treading when used for carpets.

  The thermoplastic polyamide is a polymer having an amide bond, and examples thereof include nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, and nylon 510.

  The “other fiber” may be a homopolymer or a copolymer, but preferably has crystallinity in order to maintain wear resistance. The presence or absence of crystallinity can be determined by the presence or absence of a melting peak observed in differential scanning calorimetry (DSC) measurement. If the melting peak can be observed, it can be determined that there is crystallinity.

  The melting point of “other fibers” is preferably 150 ° C. or higher in consideration of heat resistance.

  The “other fibers” preferably have crimps as well as fibers made of polylactic acid resin.

  The fraction of fibers made of polylactic acid resin in the blended yarn is preferably 30% by mass or more from the viewpoint of low environmental load. The fraction of “other fibers” in the blended yarn is preferably 30% by mass or more from the viewpoint of wear resistance and softness. That is, the fiber fraction made of polylactic acid resin in the mixed yarn is preferably 30 to 70% by mass, and the “other fiber” fraction is preferably 70 to 30% by mass.

  Examples of blending methods include combing (air entanglement) and twisting.

  Combing entangles the fibers by sucking the fibers from the mixing nozzle and striking a jet of air onto the yarn traveling through the nozzle.

  Examples of the twisting machine used for the twisting include a ring twisting machine, a cover ring twisting machine, a double twister twisting machine, a cable twister twisting machine, and an up twister twisting machine.

  Single twist and various twists can be mentioned as the types of combined twist. In single twisting, a plurality of yarns are combined in an untwisted state, and the combined yarn is twisted in one direction of Z or S. Further, the various twists are combined in a state where a plurality of yarns are respectively twisted in the same direction of Z or S, and the combined yarn is subjected to an upper twist in a direction opposite to the previous twist. Many twists are preferred when used for carpets because they have no snare (release twist) and are excellent in processability.

  The number of twists in the twisted yarn is preferably 30 to 250 T / m, more preferably 50 to 200 T / m. By setting it to 30 T / m or more, the fiber made of polylactic acid resin and “other fibers” are uniformly mixed, and generation of fluff due to scraping of the polylactic acid fiber can be suppressed. The effect of improving sex can be obtained. On the other hand, by setting it as 250 T / m or less, it can suppress that a polylactic acid fiber with a low creep characteristic generate | occur | produces a crack, and can suppress the strength reduction of a thread | yarn. In addition, in various twists, it is preferable that each of the lower twist and the upper twist of the yarn to be twisted is 30 to 250 T / m, and more preferably 50 to 200 T / m.

  The total fineness of the mixed yarn is preferably 500 to 6000 dtex, more preferably 1000 to 5000 dtex. By setting it to 500 dtex or more, it is possible to prevent see-through or the like in carpet pile use. Moreover, by setting it to 6000 dtex or less, it is possible to increase the number of stitches for carpet pile use, and to provide a sense of volume of the carpet.

  In the method for producing a dyed yarn of the present invention, “other dye” having a dyeing action different from that of the disperse dye is imparted to a mixed yarn obtained by mixing fibers made of polylactic acid resin and “other fibers”. It is important to include a step of applying a disperse dye thereafter. By doing so, both the polylactic acid fiber and the “other fibers” are dyed in a desired color while suppressing deterioration of the physical properties of the mixed fiber containing the polylactic acid fiber, and excellent dyeing. Fastness can be imparted. Specifically, the fiber made of polylactic acid resin has a weight average molecular weight retention of 90% or more compared to before dyeing, and the fastness to dyeing as a dyed yarn, that is, light fastness, friction fastness and washing fastness. Is superior to the third grade, and dyed yarns and carpets can be obtained.

The following can be considered as the mechanism.
First, when trying to dye the fiber made of polylactic acid resin and “other fiber” simultaneously with “other dye” which has different dyeing action from the disperse dye and the disperse dye, the disperse dye is put on the surface of “other fiber”. The present inventors have speculated that the “other dye” may also temporarily adhere and inhibit the “other fiber” from being dyed.
In the present invention, first, “other dye” is selectively dyed to “other fiber”, and then the disperse dye is selectively dyed to a fiber made of polylactic acid resin. Play.

Examples of the disperse dye include azo disperse dyes, quinophthalone disperse dyes, anthraquinone disperse dyes, pyridone disperse dyes, nitro disperse dyes, methine disperse dyes, and blend disperse dyes.
Examples of azo-based disperse dyes include DIANIX Yellow Brown SE-R (Dystar), DIANIX Red C-4G 150% (Dystar), DIANIX Blue S-2G (Dystar), and TERASIIL Rubine 2GFL (Ciba). Specialty Chemicals), KAYALON POLYESTER Yellow 4GE (Nippon Kayaku Co., Ltd.), KAYALON POLYESTER Red BR-S (Nippon Kayaku Co., Ltd.), KAYALON POLYESTER Blue 2R-SF (Nippon Kayaku Co., Ltd.) ), MIKETON POLYESTER Yellow Brown 2RL (manufactured by Dystar), MIKETON POLYESTER Red FL (manufactured by Dystar), MIKETONPOLYESTETE Blue G-ADW (DyStar Co., Ltd.), and the like.
Examples of anthraquinone-based disperse dyes include DIANIX Yellow AM-42 (Dystar), DIANIX Red AM-86 (Dystar), DIANIX Blue FBL (Dystar), Disperse Blue KT-1 (Tokyo Chemical Industry Co., Ltd.) Product), TERAIL Red FB 200% (manufactured by Ciba Specialty Chemicals), TERAIL Blue BGE-01 (manufactured by Ciba Specialty Chemicals), and the like.
Examples of quinophthalone-based disperse dyes include DIANIX Yellow S-3G (manufactured by Dystar), MIKETON POLYESTER Yellow 3GSL (manufactured by Dystar), and the like.
Examples of the pyridone-based disperse dye include DIANIX Flavine XF (manufactured by Dystar).
Examples of nitro-based disperse dyes include DIANIX Yellow AM-42 (manufactured by Dystar), TERATOP Yellow GWL (manufactured by Ciba Specialty Chemicals), and the like.
Examples of methine-based disperse dyes include DIANIX Yellow 7GL (manufactured by Dystar).
Examples of the mixed disperse dye include DIANIX Yellow PAL (manufactured by Dystar), DIANIX Red ASC-E01 (manufactured by Dystar), DIANIX Red CC (manufactured by Dystar), DIANIX Blue PAL (manufactured by Dystar), TERATOP Red NFR ( Ciba Specialty Chemicals), TERATOP Yellow NFG (Ciba Specialty Chemicals), CIBACET Yellow EL-F2G (Ciba Specialty Chemicals), CIBACET Blue EL-B (Ciba Specialty Chemicals), CIBACET Blue ELF Ciba Specialty Chemicals), CIBACET Black EL-FGL (Ciba Specialty Chemicals), KAYALON OLYESTER Blue B-SF conc (manufactured by Nippon Kayaku Co., Ltd.), SUMIKARON Yellow E-RPD (manufactured by Sumika Chemtex Co., Ltd.), SUMIKARON Red E-RPD (manufactured by Sumika Chemtex Co., Ltd.), SUMIKARON Blue E- RPD (manufactured by Sumika Chemtex Co., Ltd.), SUMIKARON Yellow SE-RPD (manufactured by Sumika Chemtex Co., Ltd.) and the like can be mentioned.
Examples of other disperse dyes include DIANIX Blue AM-SLR (manufactured by Dystar), TERASIIL Yellow SD (manufactured by Ciba Specialty Chemicals), CIBACET Navy FL-R (manufactured by Ciba Specialty Chemicals), MIKETON POLYESTER Yellow YL (Dyster) Amacron (American Color and Chemical), Calcosperse (American Cynamide), DIANIX Yellow Brown Dian Fast (Dystar), DIANIX Light (Dystar), Eastman Polyester (Eastman Chemical Products) ), Foron, Genacron (manufactured by Clariant), Hisperse (Maeda Kasei ( ), Interchem Polydye (manufactured by Inmont), Intrasperse (manufactured by Yorkshire Japan Co., Ltd.), Kiwalon (manufactured by Kiwa Chemical Industry Co., Ltd.), Reform (manufactured by NS Color Techno Co., Ltd.), Serilene (Yorkshire Japan Co., Ltd.) )), Terasil (manufactured by Ciba Specialty Chemicals) and the like.
A disperse dye may be used individually by 1 type, and may use multiple types together.

Examples of “other dyes” that have a dyeing action different from that of disperse dyes include direct dyes, acid dyes, basic dyes, vat dyes, sulfur dyes, azoic dyes, reactive dyes, and metal complex dyes. For example, when nylon 6 fiber is used as the “other fiber”, an acid dye, a reactive dye, a metal complex dye, or the like is better from the viewpoint of dyeing fastness.
Examples of the acid dye include Lanasyn Yellow GRL (manufactured by Clariant), Lanasyn Bordeaux RLA200 (manufactured by Clariant), Lanasyn Black M-GL (manufactured by Clariant), and Isolan Yellow GRL, Iragalan Black, etc.
“Other dyes” may be used alone or in combination.

  Examples of the dyeing method include dip dyeing and printing. Examples of dip dyeing include rose hair dyeing, tow dyeing, skein dyeing, and cheese dyeing, and textile printing includes unraveling printing, bigo printing, and the like. A package dyeing machine can be used as the dyeing dyeing machine, and a space dyeing dyeing machine or the like can be used as the dyeing machine for printing.

  Among the dip dyeing and printing, printing is preferable from the viewpoint that it is not necessary to immerse the yarn in the dyeing bath for a long period of time, and the deterioration of the weight average molecular weight and thus the physical properties of polylactic acid is suppressed.

  Space dyeing allows dyeing while running the yarn to be dyed, and dyeing with any dye in any order.

  The yarn traveling speed of space dieing is preferably 10 to 300 m / min, more preferably 50 to 200 m / min from the viewpoint of process stability and productivity.

  An example of space dieing will be described by dividing it into processes.

1. Preheating process Heat the yarn with a heater. By doing so, the thermal motion of the molecule | numerator which comprises a fiber can be activated, and a dye, especially a disperse dye can be firmly fixed to a fiber.
The heater temperature in the preheating step is preferably 90 to 120 ° C. By making it 90 degreeC or more, the thermal motion of a fiber molecule can be activated. Moreover, the hydrolysis of the polymer which comprises a fiber, especially polylactic acid can be suppressed by setting it as 120 degrees C or less.

2. Dye application process Apply dye to blended yarn. In the present invention, "other dye" is first applied, and then a disperse dye is applied. “Other dyes” and disperse dyes are kept in separate baths.

3. Temporary fixing process Heat the yarn again with a heater. By doing so, the dye is temporarily fixed to the fiber, and uneven dyeing can be reduced. The heater temperature in the temporary fixing step is preferably 90 to 120 ° C. By setting the temperature to 90 ° C. or higher, the effect of temporary fixing can be obtained. Moreover, the hydrolysis of the polymer which comprises a fiber, especially polylactic acid can be suppressed by setting it as 120 degrees C or less.

4). Steam treatment process Heat the yarn with steam. By doing so, the dye can be fixed to the fiber. In addition, the shape of the yarn is fixed by heat treatment including the preheating step and the temporary fixing step, and a carpet having a texture excellent in point feeling can be obtained by improving the snar (release twist) due to twisting at the time of carpet tufting. it can. The steam temperature is preferably 90 to 120 ° C. By adjusting the temperature to 90 ° C. or higher, the dye fastness can be improved by penetrating and diffusing dye molecules into the fiber. Moreover, by setting it as 120 degrees C or less, the hydrolysis of the polymer which comprises a fiber, especially polylactic acid can be suppressed.

5). Washing process Washing the yarn. By doing so, the unfixed dye adhering to the yarn surface can be decomposed or removed, and the dyeing fastness can be improved.
The washing liquid is preferably warm water of 30 ° C. or higher, or a solution containing a reducing agent and a reducing auxiliary agent.
The cleaning process may be provided between the temporary fixing process and the steam process, or may be provided between the steam process and a functional resin application process described later, or a functional resin application process described later. It may be provided later.

6). Functional resin application process You may provide the process of providing functional resin to a thread | yarn. Examples of functional resins include softeners, deodorants, antibacterial agents, antifouling agents, and the like.

7). Drying process The yarn is dried. An example of the drying means is a hot air dryer.

(carpet)
Examples of the aspect of the carpet of the present invention include, for example, woven carpets such as Danten, Wilton, Double Face, and Axminter, embroidery carpets such as tufting and hook drag, adhesive carpets such as bonded, electrodeposition, and cord, or those Can be used.

The mass per unit area of the tufted pile yarn in the carpet (weight per unit area) depends on the application, but for example, for a household carpet, 100 to 5000 g / m ² is preferable, and more preferably 500 to 3000 g / m. ² . Abrasion resistance can be exhibited by setting it as 100 g / m < ² > or more. On the other hand, it is economically preferable to be 5000 g / m ² or less.

  Since the carpet of the present invention is a mixture of fibers made of polylactic acid resin and other fibers, the fibers made of polylactic acid resin with low abrasion resistance are covered with other fibers, and the abrasion resistance of the polylactic acid-based carpet Sexuality can be increased. As for the abrasion resistance of the pile in the carpet, the abrasion resistance is preferably grade 3 or higher, more preferably grade 4 or higher, and further preferably grade 5 in the carpet abrasion test (number of rotations: 300).

[Measuring method]
(1) Fineness Based on JIS L 1013: 1999 8.3.1 A method, skeins of 112.5m are sampled 5 times, the mass is measured, and the value (g) is 10000 / 112.5. The apparent fineness (dtex) was determined. From the apparent fineness, a positive fineness was determined by the following formula, and an average value was calculated.
Positive fineness (dtex) = D ′ × (100 + Rc) / (100 + Re)
Where D ′: apparent fineness (dtex)
Rc: Official moisture content (%)
Re: Equilibrium moisture content (%).

(2) Deformation The cross section of the yarn was cut out and determined from the diameter D of the circumscribed circle of the single fiber cross section and the diameter d of the inscribed circle of the single fiber cross section by the following equation.
Deformity = D / d.

(3) Weight average molecular weight (Mw) of polylactic acid
Polylactic acid was dissolved in chloroform to obtain a measurement solution, which was measured by gel permeation chromatography (GPC) to determine the weight average molecular weight (Mw) in terms of polystyrene. The number of measurements was 5, and the average value was calculated.

(4) Melting point Using a Shimadzu differential scanning calorimeter DSC-60, manufactured by Shimadzu Corporation, a 2.0 mg sample was measured at a heating rate of 20 ° C./min, and the temperature giving the extreme value of the obtained melting endothermic curve was the melting point. (° C). The number of tests was 5, and the average value was calculated.

(5) Tensile strength and tensile elongation (standard time test)
Measured according to JIS L 1013: 1999 8.5.1.
With the sample loosely tensioned, it was attached to the grip of a tensile tester (Tensilon (registered trademark) UCT-100 manufactured by Orientec Co., Ltd.) with a grip interval of 200 mm, and the test was performed at a constant speed extension of a tensile speed of 200 mm / min. . Read the elongation when the initial load is applied as looseness (mm), further pull the sample, measure the load and elongation (mm) when the sample is cut, and use the following formula to determine the tensile strength (cN / dtex) and tension The elongation (%) was calculated. The number of tests was 10, and the average value was calculated.
T _b = SD / F ₀
Here, T _b : Tensile strength SD: Strength at cutting F ₀ : Positive fineness elongation of sample (%) = [(E ₂ −E ₁ ) / (L + E ₁ )] × 100
Here, E ₁ : Looseness (mm)
E ₂ : Elongation at the time of cutting (mm)
L: Grasp interval (mm).

(6) Light fastness Measured based on JIS L 0842: 1996 (Testing method for fastness to dyeing with respect to ultraviolet carbon arc lamp light).

A test piece having a width of 70 mm and a length of 200 mm along the longitudinal direction of the carpet original fabric was cut out, urethane was attached to the back of the original fabric, and the pile surface was attached to the testing machine with the light source facing the light source. When testing the dyed yarn, the dyed yarn was affixed to a drawing paper having a width of 70 mm and a length of 200 mm so as not to leave a gap, thereby obtaining a test piece. The tester uses a carbon arc lamp type light resistance tester (Suga tester), with one carbon arc, 250 mm distance from the light source to the test piece, 55 to 65 ° C. in-machine temperature, 63 ± 3 black panel temperature of the test stand 1st grade by comparing the discoloration color of each of the test piece and the gray scale for discoloration (JIS L 0804: 1994) by exposing at 40 ° C., relative humidity 30-50%, sample rotation speed 3-4 times / min, irradiation time 40 hours. To 5th grade.
Grade 5: The color change is about gray scale No. 5 for discoloration.
Grade 4: Color change is about gray scale No. 4 for discoloration.
Grade 3: The color change is about gray scale No. 3 for discoloration.
Second grade: The color change is about gray scale No. 2 for discoloration.
First grade: A color change of the gray scale No. 1 for color change or over that.

(7) Friction fastness Measured based on JIS L 0849: 1996 (Test method for fastness to dyeing against friction).

The original carpet was cut into a width of 30 mm and a length of 200 mm to obtain a test piece. A white cotton cloth was placed on the contact surface of the friction element and fixed on the test stand of the testing machine. In the case of testing the dyed yarn, the dyed yarn was attached to an image paper having a width of 30 mm and a length of 200 mm so that there was no gap, thereby obtaining a test piece. The load applied to the friction element is 1.96 N, and the reciprocating friction is performed 100 times at a speed of reciprocating about 30 times per minute between 100 mm of the test piece. Thereafter, the respective contaminations of the white cotton cloth and the gray scale for contamination (JIS L 0805: 1998) were compared, and grades 1 to 5 were evaluated. The tester used was a friction tester type II (Gakushin Type). The white cotton fabric for friction uses pure cotton yarn, count is 30s long, 36s wide, density is 72 vertical / 25.4mm vertical, 69 horizontal / 25.4mm, dry (DRY) and wet (WET) ) Was evaluated. When wet, a white cotton cloth was soaked in water for 10 minutes, sandwiched with filter paper and lightly pressed, and the measurement was performed. The degree of contamination was evaluated immediately after the measurement.
Grade 5: Color change is about gray scale No. 5 for contamination.
Grade 4: The color change is about gray scale No. 4 for contamination.
Grade 3: The color change is about gray scale No. 3 for contamination.
Second grade: The color change is about gray scale No. 2 for contamination.
First grade: A color change of about 1 or more than the gray scale for contamination.

(8) Washing fastness It evaluated based on JIS L 0844: 1997 A-1 method (dye fastness test method for washing).
A sample having a length of 100 mm and a 1 g sample is taken, and the sample is arranged between two pieces of predetermined nylon and cotton-attached white cloth having a width of 40 mm and a length of 100 mm, and the four sides are sewn together with white cotton thread. Put 5 g / L of soap and 100 mL of water in a test bottle attached to a round meter type laundry tester and preheat to 40 ° C. One test piece was placed in a test bottle, attached to a tester that was sealed and maintained at a temperature of 40 ° C., and rotated for 30 minutes. The test piece was sandwiched between dry filter papers, dehydrated by lightly pressing, cut off so that the test piece and the attached white cloth were in contact with one side of the seam, and dried with a dryer at 60 ° C. or lower. After the test, the change color of the sample is changed to gray scale for change color (JIS L 0804: 1994), the contamination to nylon (contamination 1) and the contamination to cotton (contamination 2) to gray scale for contamination (JIS L 0805: 1998). And grades 1 to 5 were evaluated. As the soap, JIS K 3302 “Solid Laundry Soap” (1995) additive-free was used. As the white cloth, JIS L 0803 “Attached white cloth for dyeing fastness test” (1998), which had been previously removed, scoured and bleached, was used.
(Discolor)
Grade 5: The color change is about gray scale No. 5 for discoloration.
Grade 4: Color change is about gray scale No. 4 for discoloration.
Grade 3: The color change is about gray scale No. 3 for discoloration.
Second grade: The color change is about gray scale No. 2 for discoloration.
First grade: A color change of the gray scale No. 1 for color change or over that.
(pollution)
Grade 5: Color change is about gray scale No. 5 for contamination.
Grade 4: The color change is about gray scale No. 4 for contamination.
Grade 3: The color change is about gray scale No. 3 for contamination.
Second grade: The color change is about gray scale No. 2 for contamination.
First grade: A color change of about 1 or more than the gray scale for contamination.

(9) Existence of fluff generation The presence or absence of fluff was counted in 1 m of the length of the twisted yarn, and evaluated as follows. The number of tests was 10, and the average value was calculated.

(10) Presence or absence of cracks The sample was cut to a length of 10 mm, and the sample was coated with silver using a Hitachi E-1010 vapor deposition device. Cracks were cracked at a magnification of 500 times using a Hitachi 3500N scanning electron microscope (SEM). The presence or absence was evaluated.

(11) Fabric weight of pile yarn The carpet after the tuft was cut into a 50 cm square, the total mass of the pile yarn in the sample was measured, and the basis weight of the pile yarn was calculated per unit area (1 m ² ).

(12) Processability of carpet The processability during carpet processing was evaluated as follows.
○: No thread breakage occurs during tufting.
Δ: Some thread breakage occurs when tufting.
×: Many yarn breaks occur during tufting.

(13) Point feeling of the carpet The carpet was touched by hand, and the point feeling which is one of the textures was evaluated as follows.
○: Excellent point feeling.
Δ: There is not much point feeling.
X: There is no point feeling at all.

(14) Volume feeling of carpet The carpet was touched by hand, and the volume feeling which is one of the textures was evaluated as follows.
○: Excellent volume.
Δ: There is not much volume feeling.
X: There is no volume feeling.

(15) Flexibility of carpet Carpet was touched by hand, and the flexibility as one of the textures was evaluated as follows.
○: Excellent flexibility.
Δ: Not very flexible
X: There is no flexibility and it has a hard texture.

(16) Abrasion of carpet JIS L 1096: 1999 8.17.3 In accordance with the Taber method, H-18 wear wheels are used, and a load of 1 kgf (9.8 N) is applied to each pair of left and right wear wheels. Then, the carpet was worn by rotating a predetermined number of revolutions, and then the grades of grades 1 to 5 were visually determined for changes in the unworn portion and the worn portion. The number of rotations was 300. The number of tests was three, and the average was determined as wear.
5th grade: Unacceptable.
Grade 4: Slightly recognized but almost inconspicuous.
3rd grade: Obviously recognized, but less noticeable.
Second grade: Somewhat remarkable.
1st grade: Very remarkable.

[Examples 1 to 4]
(Polylactic acid fiber yarn)
L-form polylactic acid chips with an optical purity of 98% are melt-spun, crimped by a heated fluid crimping device, made of flat fibers with a single fiber cross-section of 1.6, total fineness of 1450 dtex, number of filaments 54 polylactic acid fiber yarns having crimps were obtained.
The polylactic acid fiber yarn at this stage had a tensile strength of 1.79 cN / dtex, a tensile elongation of 45.1%, and a weight average molecular weight of 17.5 × 10 ⁴ .

(Nylon 6 fiber yarn)
Nylon 6 chips are melt-spun, crimped by a heated fluid crimping device, and the crimped nylon 6 has a cross-sectional shape of a single fiber with a Y cross-section with an irregularity of 3.0, a total fineness of 1170 dtex, and a filament number of 54 A fiber yarn was obtained.

(Mixed yarn)
The polylactic acid fiber yarn and the nylon 6 fiber yarn were each subjected to a lower twist of 180 T / m in the S direction and combined, and the combined yarn was subjected to an upper twist of 180 T / m in the Z direction.
The yarn made of polylactic acid fibers at this stage had a tensile strength of 1.74 cN / dtex, a tensile elongation of 42.7%, and a weight average molecular weight of 17.5 × 10 ⁴ . Moreover, there was no crack in the polylactic acid fiber yarn.
Further, the twisted yarn had no fluff.

(staining)
The above-mentioned twisted yarn was dyed with a space dyeing dyeing machine while running the twisted yarn at a speed of 150 m / min.
(Preheating process)
The running yarn was heated with a heater at the preheating process temperature described in Table 1.
(Dye application process)
The running yarn was passed through a pre-bath containing 5 g / L of acid dye (Lanasyn Bordeaux), 5 g / L of leveling agent, 10 g / L of acetic acid, and 5 g / L of light-proofing agent.
Next, the running yarn was passed through a bath after containing 35 g / L of a disperse dye (Teratop Red NFR), 5 g / L of leveling agent, 10 g / L of acetic acid, and 5 g / L of light-proofing agent.
(Temporary fixing process)
The running yarn was heated with a heater at the temporary fixing process temperature shown in Table 1 to temporarily fix the dye to the fiber.
(Steam treatment process)
The running yarn was heated with steam at the steam treatment process temperature shown in Table 1 to fix the dye to the fiber.
(Washing process)
The running yarn was washed with water at 50 ° C.
(Functional resin application process)
The running yarn was passed through the bath after the softener 10 g / L was added.
(Drying process)
The running yarn was dried at 150 ° C. with a warm air dryer.
The yarn passed through the above steps was wound up to obtain a dyed yarn.
In all of Examples 1 to 4, there was no crack in the polylactic acid fiber yarn in the dyed yarn.
In all of Examples 1 to 4, the dyed yarn had no fluff.

(Base fabric)
A spunbonded nonwoven fabric having a basis weight of 120 g / m ^{2 made} of polyethylene terephthalate was used as a carpet base fabric.

(Toughing)
The dyed yarn was tufted on the base fabric with 1/8 gauge and stitch 7.5, and the tip of the pile was cut to make a household carpet having a pile length of 10 mm and a pile weight of 1100 g / m ² .
In all of Examples 1 to 4, there was no yarn breakage during carpet processing.

[Comparative Examples 1-4]
(Polylactic acid fiber yarn)
The same one as used in Example 1 was used.

(Nylon 6 fiber yarn)
The same one as used in Example 1 was used.

(Mixed yarn)
The same one as used in Example 1 was used.

(staining)
The above-mentioned twisted yarn was dyed with a space dyeing dyeing machine while running the twisted yarn at a speed of 150 m / min.
(Preheating process)
The running yarn was heated with a heater at the preheating process temperature described in Table 1.
(Dye application process)
The running yarn was passed through a pre-bath containing disperse dyes (Teratop Red NFR 35 g / L, leveling agent 5 g / L, acetic acid 10 g / L, and light fastness 5 g / L).
Next, the running yarn was passed through a bath after containing 5 g / L of acid dye (Lanasy Bordeaux), 5 g / L of leveling agent, 10 g / L of acetic acid, and 5 g / L of light fastness agent.
(Temporary fixing process)
The running yarn was heated with a heater at the temporary fixing process temperature shown in Table 1 to temporarily fix the dye to the fiber.
(Steam treatment process)
The running yarn was heated with steam at the steam treatment process temperature shown in Table 1 to fix the dye to the fiber.
(Washing process)
The running yarn was washed with water at 50 ° C.
(Functional resin application process)
The running yarn was passed through the bath after the softener 10 g / L was added.
(Drying process)
The running yarn was dried at 150 ° C. with a warm air dryer.
The yarn passed through the above steps was wound up to obtain a dyed yarn.

(Base fabric)
The same one as used in Example 1 was used.

(Toughing)
The dyed yarn was tufted onto the base fabric in the same manner as in Example 1 to obtain a carpet.

  According to the present invention, it is possible to produce a dyed yarn made of polylactic acid which is excellent in fiber properties and has no practical problems in factory production. As for textile products using the above-mentioned twisted yarn, for example, carpet use, it can be used as an automotive option mat, a reception room carpet, a guest room carpet, a household rug, etc. utilizing a soft texture, volume feeling or point feeling. It is very useful.

Claims (6)

  It includes a step of adding another dye having a dyeing action different from that of a disperse dye to a mixed yarn in which fibers made of polylactic acid resin and other fibers are mixed, and then adding a disperse dye. A method for producing dyed yarn.   The method for producing a dyed yarn according to claim 1, wherein the other dye and the disperse dye are applied while the mixed fiber is running.   The method for producing a dyed yarn according to claim 1 or 2, wherein a thermoplastic polyamide is used as the other fiber.   Fibers made of polylactic acid resin and disperse dyes are mixed with other fibers dyed with other dyes having different dyeing action, and both fibers made of polylactic acid resin and the other fibers are mixed Dyeed, the polylactic acid resin has a weight average molecular weight of 130,000 or more, the tensile strength of the fiber made of the polylactic acid resin is 1.5 cN / dtex or more, and light fastness and friction fastness as a dyed yarn The dyed yarn is characterized in that the fastness to washing is grade 3 or higher.   The dyed yarn according to claim 4, wherein the other fibers comprise thermoplastic polyamide.   A carpet using the dyed yarn according to claim 4 or 5.